Intro to C# Coding

Date: Monday, January 6th

Description: Course introduction, setting up applications we’ll be using, learning about C# basics

About: Visual Studio

What

  • Free, integrated development environment (IDE)

Key Features

  • Coding & debugging

  • Project templates for application development

  • Integrated (built-in) tools (e.g. GIT, testing tools, diagnostics)

  • Optional extensions for customizing & enhancing functionality

  • Cross-platform development (meaning apps created on VS can be used on diff machine types)

Ideal Use Cases

  • Learning a new programming language

  • Building small to medium-scale applications

.NET Platform

  • Free, open-source, development platform that facilitates cross-platform development

  • Supports the use of tools like…

    • Visual Studio

    • Visual Studio Code

  • Creating several different types of software:

    • Web apps

    • Web services

    • Desktop apps

    • Mobile apps

    • Cloud apps

    • Cloud services

    • Microservices

What is the C# Programming Language?

  • Statically-typed

  • Pure object-oriented programming language

  • runs on .NET framework

  • Similar to Java & C++

  • Use to build several diff types of software:

    • Business applications for storing & analyzing data

    • Dynamic web applications that can be accessed from a web browser

    • Games (2D & 3D)

    • Financial & scientific applications

    • Cloud-based applications

    • Mobile applications

First Code in C#

Console.WriteLine("Hello World!");

Reading Error Messages in C#

#INPUT
console.WriteLine("Hello World!");
#OUTPUT
(1,1): error CS0103: The name 'console' does not exist in the current context

  • console should be capitalized (C# is case-sensitive)

  • (1,1) in error message suggests likely location of error

    • (line, character)

    • in this case —> error is at line 1, character 1

Common Mistakes New C# Programmers Make

  • Entering lower-case letters instead of capitalizing C in Console, or the letters W or L in WriteLine.

  • Entering a comma instead of a period between Console and WriteLine.

  • Forgetting to use double-quotation marks, or using single-quotation marks to surround the phrase Hello World!.

  • Forgetting a semi-colon at the end of the command.

How to Make Comments in C#

To make a single-line comment:

  • Add // at beginning of the line of code

To make a multiline comment:

  • Add */ or /* at beginning of the line of code

Example: 

// This line of code is a comment
Console.WriteLine("This is not a comment"); /* This is another comment

Difference b/w Console.Write & Console.WriteLine

Console.Write()

  • prints a message without adding a new line at the end

  • any subsequent output will appear on the same line

Example

Console.Write("Hello");
Console.Write(" World!");

Output 

Hello World!

Console.Write()

  • prints a message and automatically adds a new line at the end

  • any subsequent output will appear on the next line

Example

Console.WriteLine("Hello");
Console.WriteLine("World!");

Output

Hello
World!